Fundus camera, including eye fixation means



Feb. 26, 1952` J. H. MGMILLIN FUNDUS CAMERA, INCLUDING EYE FIXATION MEANS 2 SHEETS-SHEET l Filed March 17|, 1947 38 [lll/lll' 203 jjj (Ittornegs Feb. 26, 1952 J. H. MCMlLLlN FUNDUs CAMERA, INCLUDING EYE FIXATION MEANS 2 SHEETS--SHEET 2 Filed March 1?, 1947 IIV/ 7 Cttornegs Patented Feb. 26, 1952 UNITED STATES PATENT CFFICE FUNDUS CAMERA, INCLUDING EYE FIXATION MEANS 2 Claims.

This invention relates to photography, and in particular, to cameras for photographing the fundus of the eye, namely the portion of the interior of the eye which lies opposite and in back of the pupil.

One object of this invention is to provide a fundus camera which is so arranged as to eliminate the reflection of light from the cornea of the eye and enables photographs to be taken of the interior of the eye by means of light furi nished by a self-contained illuminating system.

Another object is to provide a fundus camera which is light in weight, compact and suiciently small to be held in the hand while the photographs are being taken.

Another object is to provide a fundus camera which is used in conjunction with a speculum or rest placed in contact with the eyeball outside the margins of the cornea and beneath the eyelids, the eyeball being previously anesthetized t enable the patient to tolerate the speculum.

Another object is to provide a fundus camera wherein the interior of the eye is illuminated for focussing purposes by an incandescent lamp which, after focussing, is subjected momentarily to a current overload so as to provide a sudden increase of illumination of short duration while taking the photograph.

Another object is to provide a fundus camera wherein a pair of luminous fixation objects are provided in the antechamber of the camera on which the patient xes his gaze in alternate succession for alternate exposures, rotating his eyeball from one to the other in so doing, and thereby enabling stereoscopic photographs to be taken.

Another object is to provide a fundus camera, as set forth in the preceding objects, wherein a single trigger or operating member when actuated rst illuminates the lamp at normal illumination for focussing purposes, and when further depressed, super-illuminates the lamp with an overload current and at the same time, actuates the shutter to expose the film.

Another object is to provide a fundus camera, as set forth in the object immediately preceding, wherein the same trigger or operating member also moves a prism of the focussing system out of the path of the rays to the shutter immediately before the shutter is released.

Another object is to provide a fundus camera, as set forth in the preceding objects, wherein the light from the illuminating system enters the eye through one aperture in the nose of the camera and re-enters the camera through another aperture on its way to the viewing system or to the film, the two apertures being separated from one another by an opaque bridge portion which masks out the image of the lamp from the cornea acting as a convex mirror and prevents this brilliant image from being photographed on the film and therefore from interfering with the photographed image of the fundus.

In the drawings:

Figure 1 is a central vertical section through a fundus camera according to a preferred form of the invention, with the brow rest omitted and with the movable prism of the viewing system shown in its lowered or viewing position and with the lamp normally illuminated;

Figure 2 is an approximately vertical section taken along the zigzag line 2-2 in Figure 1;

Figure 3 is an approximately vertical section taken along the zigzag line 3 3 in Figure 1;

Figure 4 is an approximately horizontal section mainly along the optical axis of the camera and taken along the zigzag line 4 4 in Figure l;

Figure 5 is a fragmentary front elevation of the nose of the camera;

Figure 6 is a diagrammatic side elevation of the fundus camera of Figures 1 to 5 inclusive, showing the nose of the camera resting against a speculum which engages the eyeball beneath the eyelid, and also showing the brow rest in use;

Figure '7 is a front elevation of a speculum or camera rest shown in use in Figure 6; and

Figure 8 is a central vertical section through the speculum shown in Figure '7, taken along the line 8-8 therein.

Figure 9 is an approximately horizontal section through a modied visual fixation device adapted to be inserted in the plane 9-9 of Figure 1.

Referring to the drawings in detail, Figures 1 and 3 show a fundus camera, generally designated I0, according to a preferred form of the invention and used in conjunction with a speculum or rest, generally designated II (Figures 7 and 8). The camera I0 is contained in a casing I2 consisting of oppositely-iacing cooperating casing halves I3 and I4 (Figure 3) engaging one another along their meeting edges I5 and I6 respectively. The casing halves I3 and I4 are held together by screws I1 (Figures 2 and 6) which pass through the former and are threaded into the latter.

Frame structure The optical elements and other working parts of the camera in the interior thereof are for the most part mounted upon a frame structure or chassis, generally designated I8, of irregular shape occupying the interior of the camera and secured by the screws I9 and 2li (Figure 2) to the casing halves I3 and i4 respectively. The iorward portion of the frame structure I3 passes through an aperture 2l and terminates in a nose plate 22 in the form of a circular disc with vertically spaced apertures 23 and 24. The rearward portion of the frame structure I3 passes through an aperture 2.5 in the rearward wall of the casing I2, and is in part supported by the edges of the apertures 2I and 25.

The frame structure I6 is provided with a hori zontal partition portion 26 which divides the casing l2 into an upper compartment occupied by the photographic system and a lower compartment occupied by the illumination system. EX- tending downward from the partition portion 26 is a plate-like portion 39 which is secured by the screws 3l to the casing half I3.

Illuminating system The illuminating system, generally designated 32, :for illuminating the interior of the eye in order to provide light for photographing the funv dus, is housed in the lower portion of the casing I2 (Figures l, 2 and 3). The casing I2 is provided with a hole 33 in the lower' end of the handle portion 34 thereof. Passing through the hole 33 into the interior of the camera is a cable 35 which is connected externally to a source of electric current and which is provided with a pair of conductors 36 and 31 respectively. The conductor 36 leads to one terminal 38 of an incandescent larnp socket 39 having an incandescent lamp 46 threaded into the socket bore 4I and having a filament 42 which' is illuminated in the ordinary manner when supplied with electric current through the conductors 36 and 31.

In order to provide an adjustment for centering the iilament 42 of the lamp 40 relatively to the lens'system of the illuminating system 32, the socket is mounted upon a movable plate 43 which is secured to the downwardly extending portion (i4 of the frame structure I8 by a screw 45 passing through an enlarged hole 46. A pair of adjusting screws 4l (Figure 2) passing through threaded holes in the bosses 48 in the casing halves I3 and I4 enables the plate 43 and socket 39 to be shifted to and fro until its position of best adjustment is reached relatively to the optical system. described below. A leaf spring 49 mounted on a stud U on the frame portion 44 engages the top of the swinging plate 43 and urges the latter downward toward the adjusting screws 41.

In order to provide fixation. points for the patients gaze in taking stereoscopic photographs, a pair or" bent rods 5I of transparent plastic material are mounted with their lower ends adjacent the lamp 46 and lead upward through vertical holes 52 in the partition portion 26 of the frame structure i3. The rods 5I are provided at their upper ends with spherical knobs 53 which serve as nxation points, as described below in connection with the operation of the instrument. The rods 5i conduct light upward from the lamp lament ll to the knobs 53 and illuminate the latter, which are preferably of a deep red color in order not to tog the patients vision.

Extending horizontally rearward from the frame structure portion 44 at the bottom thereof r is a, portion 54 having a downwardly bent projection 55 which is connected to the plate-like portion and is parallel to a projection 56 likewise'connected to the portion 36. The projections 55 and 66 are bored in alignment to receive 'the plate-like portion 30.

an operating plunger rod 51 carrying a push button or head 58 which extends through an aperture 59 in the casing I2. The rod 51 and push button 53 are urged to the left by a coil spring 66 surrounding the rod 51 and mounted between the projection and the push button 58.

The rod 51 is of insulating material such as plastic or hard rubber and is provided with a groove 6I containing an annular band 62 of conducting material, such as copper or brass. En gageable with the upper side of the band 62 is a contact 63 mounted on a spring arm 64 which also carries a second contact 65 mounted to the rear of the iirst contact 63. The spring arm 64 (Figures l and 3) is mounted upon an ininsulating stud 66 inserted in an aperture 61 in A screw 68 secures the spring arm 64 against the insulating stud 66 and also in engagement with a conductor 69 which runs to the terminal 10 of the electric light socket 36. The spring arm 64 is preferably or spring brass or other resilient material.

Also simultaneously engageable with the band 62 (Figures 2 and 3) is a contact 1I mounted on a spring arm 12 which is secured to an .nsulating stud 13 mounted in an aperture 'I4 in the plate-like portion 30 by a screw 15 threaded therein. The screw 15 also engages the upper end of a conductor 16, the lower end of which is connected to one terminal 11 of a resistor 18,

the opposite terminal 19 of which is connected.

by a conductor to a screw BI. The latter, like the screw 15, is threaded into an insulating stud 32 mounted in an aperture in the plate-like portion 36 and also securing thereto a spring arm S3 carrying a contact 84 mounted immediately oppositely opposite the contact 65 so that the contacts 84 and 65 are interconnected by the conducting band `62 on the rod 51 when the push button 53 is pushed inward. The screw BI also engages and holds the upper end of the conductoi1 3l'. The casing 85 of the resistor 18 is secured by the screws 86 to the casing half I3.

The illuminating system 32 also includes a condensing lens system, generally designated 81,A which projects the light from the incandescent f BB is a second convex condensing lens 32 spaced axially away from the condensingr lens S6.

Mounted adjacent the condensing lens 92 is a right-angle reiiecting prism 93, the hypotenuse surface of which is preferably tilted and backed by a cover plate 94 holding the prism 33 and lens 62 in an annular recess 95. he aperture 24 in the nose plate' 22 opens into the upper portion of the prism 63 and serves to pass the light rerlected by it into the interior of the eye. The bridge portion 56 between the two apertures 24 and 23 (Figures l and 5) is of a sufficient width to serve as a mask for blocking out the imagev of the lamp 46 which would otherwise be reflected directly from the cornea of the eye into the photographic objective and thence recorded upon the film.

Photographic and viewing system The photographic system, generally designated 91, occupies the upper part of the casing 2 and cooperates with a viewing system, generally designated 98, provision being made for shifting rapidly from one system to the other as thev focussing operations are completed and the eX- posure is made. The side walls of the casing halves I3 and |11 (Figure 4) are provided with parallel vertical guide surfaces 99 and |00 andalso with upper horizontal guide surfaces (Figures 1 and 2), the surfaces |0| lying in the same plane partly on the casing half I3 and partly on the casing half I4 so as to form continuations of one another. A lower guide surface |02 parallel to the guide surfaces |0| is formed on the frame structure or chassis I8.

Mounted in the rectangular opening formed by the guide surfaces 99 to |02 inclusive is a rectangular lens mount |03 which is reciprocable horizontally to and fro between forward and rearward abutments |04 and |05 respectively (Figures 1 and 4). The lens mount |03 is provided with an extension |96 projecting .downward through an opening |01 in the frame structure I9 and having rack teeth |98 meshing with the teeth of a pinion |09 mounted on a horizontal shaft The shaft |||l is journaled in spaced parallel bearing brackets Hl and ||2 secured to and extending downward from the frame structure I8 (Figure 2) on opposite sides of the pinion |09. One end of the shaft ||0 extends outward through a hole ||3 in the casing half I4 and terminates in a knurled head II4. By rotating the knurled head ||4 with the fingers, the lens mount |93 is caused to move to and fro along its guide surfaces 99 to |92 for focussing purposes.

Any suitable type of photographic objective may be mounted in the lens mount |93, a single double-convex lens H5 being shown merely for purposes of simplication. The ordinary highlycorrected photographic lens usually consists of two or more components and sometimes consists of several spaced doublets or triplets. The photographic objective ||5 is mounted in the threaded counterbore ||6 (Figure l) and is held in position against an annular flange ||1 by a .11

threaded retaining ring IIS mounted in the counterbfore HG. The annular flange II'I is provided with an aperture |'9 through which the rays of light pass either to the viewing system or to the film.

The viewing system 98 occupies the eXtreme upper portion of the casing I2 and is mounted partly in a tubular casing extension |20 at the top of the instrument. 1n order to shift from the photographic system 91 to the viewing system S8, a verticallyV reciprocable right-angle prism |2| is provided (Figure 1). The prism 2| is mounted in a cell |22 which is reciprocable vertically within an elongated cage-like guide frame |23.. The guide frame |23 is provided with lower edge flanges |24 by which the frame |23 is secured to the partition portion 26 of the frame structure 8, as by the screws |25. Extending downward from the partition portion 26 is a tubular portion |26 of rectangular cross-section which is co-extensive with the guide frame |23 and forms a continuation thereof for the reciprocation of the cell |22 containing the prism |2|.

An arm portion |21 extends horizontally rearward from the prism cell |22 and terminates in a yoke portion carrying a pivot pin |28. Pivotally connected to the pivot pin |28 is the upper end of a link |29, the lower end of which is connected by a pivot pin |30 to the upper portion |3| of a bell crank lever |32. The lower portion 6 of the bell crank lever |32 is provided with an elongated slot |34. A pin |35 mounted in the reduced diameter end portion |36 of the plunger rod 51 engages the slot |34 and swings the bell crank lever |32 around a pivot stud |31 which in turn is threaded into a boss |38 on the platelike portion 30 of the frame structure i8. As a consequence, when the switch button 58 is pushed inward, the reciprocation of the plunger rod 51 and the consequent swinging of the bell-crank lever |32 causes the prism cage |22 and prism |20 to move from the position shown in Figure 1 to the ,dotted line position thereof, reciprocating vertically within the guide frame |23 and extenfsion |25.

Mounted adjacent an aperture |39 in the upper end of the guide frame |23 is a right-angle prism |40. The casing extension |29 terminates in an annular recess containing an eye-.piece lens cell 42 having a threaded counterbore I 43 carrying a threaded retaining ring |44J which holds an eye-piece lens |45 within the counterbore |43 against an annular ilange |49. The casing eX- tension |21 terminates in an inwardly-extending annular flange |41 forming a window for the eye of the user. In order to exclude extraneous light, a conventional tubular eye cup oi shade (not shown) of rubber or other suitable material, may be mounted on the end of the casing extension |29. For purposes of simplication, the eye-piece lens system has been shown as consisting of a single double-convex lens |45, whereas in actual practice, this lens may consist of several components, as is well known in the optical instrument art.

Mounted behind the prism cell |22 is an extension |48 of the frame structure |8 is a shutter |49 which reciprocates horizontally in a recess |59 formed in the rearward wall of a vertical platelike portion |5| integral with the frame extension |49I (Figures 1 and 4). The portion |5| is provided with a central aperture |52 of rectangular outline across which the shutter |49 reciprocates, the latter being provided with a vertical slit |53 for exposing the nlm |54 placed behind it in a magazine |55. 'The magazine |55 is provided with a forward flanged portion |56 secured by the screws |51 to the portion |5| and thereby retaining the shutter |49 within its recess |50. The

` shutter |49 is provided with a pin |58 (Figure 4) forming a handle by which the shutter may be moved to its set position prior to making an exposure.

The shutter |49 is also provided with a forwardly extending arm or catch |59 to which is attached one end of a coil spring |69, the opposite end of which is secured to an arm |5| connected to the frame structure extension |48. The catch |59 is engaged by the upper end |62 of a shutter release lever |53 (Figure l) which extends upward into the extension |48 through a slot |54. The shutter release lever 63 is pivotally mounted upon a pivot stud |65 threaded into the plate-like portion 30 of the frame structure i8 and is provided with a coil spring |56 secured at one end to the pin |51 on the lever |63 and at the other end to a boss |68 on the inside of the casing half I3. The lower portion |69 of the shutter release lever |53 is engaged by the rearward end of the reduced diameter portion |36 of the plunger rod 51 when the push button 58 is pressed inward its full distance.

The nlm magazine and the arrangement for handling and shifting the nlm |54 may be of any conventional type and its details form no part of Brow rest Rising from the top of the casing extension |20 (Figure 6), is a brow rest support |18 having a horizontal bore |1| therethrough. Slidably mounted in the bore |1| is a screw-threaded rod |12, the threaded portion |13 of which is engaged by a knurled thumb-nut |14 mounted in a slot |15 in the support |18. Rotation of the rod |12 is prevented by a groove |18 therein engaged by the tip |11 of a stud 18 threaded through a hole |19 leading to the bore |1|. The outer end of the rod |12 carries a pivot pin |89 which passes through ears |8| extending rearwardly from a brow rest pad |82. The latter' is suitably configured to engage the brow or forehead of the patient and may have its forward surface |83 slightly concave for this purpose. To adjust the brow rest, the operator rotates the thumb nut |14 in one direction or the other, causing the rod |12 and the pad |82 to advance or recede relatively to the patients forehead.

Speculum The speculum (Figures 8, 7 and 8) serves as a rest and also a support for positioning the camera I8 accurately with respect to the eyeball. For this purpose, the speculum I I consists of a handle |84 having an annular portion |85 on the end thereof. Extending transversely from the plane of the annular portion |85 is a shallow cup portion |88` having an annular wall |81 parallel to the annular portion |85 and with a central aperture |88. Extending rearwardly at an angle to the annular portion |81 are two contact portions |89 of arcuate cross-section and partly annular form. The marginal portions of the inner surfaces |90 of the contact portions |89 are concave with a curvature approximately the same as the curvature of the eyeball adjacent the cornea. The cupshaped portion |86 forms an annular recess IBI for the reception of the nose plate 22 of the camera |0, and is of substantially the same diameter and thickness. The forward surface 92 acts as a stop for the forward surface of thenose plate 22.

Operation In the operation of the invention, the magazine |55 is loaded with suitable film |54 and placed in its position in the camera. The plug on the end of the cable is connected to a suitable source of current for energizing the conductors 38 and 31. The eyeball is then anaesthetized in order to render it insensitive to the pressure of the speculum The eyelids L are then lifted and the contact portions |89 of the speculum l inserted beneath them with the inner surfaces |98 engaging the outer surface of the eyeball E in the area or zone surrounding the cornea C.

The eyeball E is then in a position for receiving light through the cornea C, the pupil P and the lens O so that the fundus F will beilluminated for viewing and photographing. It will bevseen that the speculum I projects forward a suflicient distance so that the cornea C is free from contactwith any portion of the speculum I The operator then grasps the handle portion 34 in his hand and places the nose plate 22 in,

its socket |9| in the front part of the speculum Ii, so that it comes to rest against the surface |92. The camera l0 is now placed accuratelyin position with respect to the fundus F to be photographed. The operator now adjusts the browA rest pad |82 by moving it to and fro until it engages the brow B and provides an additional steadying point for the camera |D, this beingl done by rotating the knurled thumb nut |14.

The optical and mechanical partsA of the camera I0 are now in the position of Figure 1, with the prism |2| intercepting the rays which would otherwise .pass from the photographic objective ||5 to the iilm |54. When these adjustments have been made and the camera is properly positioned, the operator closes the switch (not shown) which energizes the conductors 36 and 31 in the cable 35. The current then flows through the circuit consisting of the conductors 31 and 80, the resistor 18, the conductor 16, the spring arm 12, contact 1|, band 82, contact 83, spring arm 84, conductor 89, filament 42 of the lamp 40 and conductor 38. The cricuit thus established lights the filament 42 of the lamp 48 with its normal brilliance.

Light from the filament 42 follows the path indicated by the chain line in Figure 6. It passes through thecondensing lens system 81 and is relectedby the prism 93 through the aperture-24 i and the speculum aperture |88 into the interior of the eye E, illuminating the fundus F. The light which is directly reflected from the cornea C acting as a convex mirror, is intercepted by the bridge vportion 96 of the nose plate 22 and is prevented from entering the camera. The light reected from the fundus F, however, retraces.

its path through the eye E and passes through the aperture 23 into the interior 0f the camera. There it is refracted by the lens ||5 and twice reflected by the prisms |2| and |40 and finally passes through the eyepiece lens |45 into the eye of the operator. Thus, the light follows the path indicated by the chain line in Figure 6.

As the operator observes the image of the fundus through the eyepiece lens |45, he racks the lens mountv |83 back and forth by rotating the knurled head ||4 on the pinion shaft |18 until the image seen through the eyepiece lens |45 is sharply focussed. The optical elements in the viewing system 98 are so spaced and mounted relatively to the photographic objective I I5 that when the image formed by the latter is in sharp focus when viewed through the eyepiece lens |45, it will also be in sharp focus upon the film |54 when the prism |2| is moved aside and the shutter |49 is tripped to make thel exposure.

Thus, when the operator has focussed the image of the fundus sharply by means of the hand wheel or knurled head ||4, he depresses thepush button 58 to make the exposure. In so doing, he pushes the plunger rod 51 rearward (Figure 1) against the urge of the coil springv 80, consequently moving the conducting bandY 62 rearward so that it breaks thecircuit between the contacts 1| and 83 and closes the circuit between the contacts 84 and 65. This shunts outthe resistor 18 so that the full voltage is supplied to the filament 42 instead of a reducedvoltage by way'of lthe resistor 18 as before. Thiscauses 9 the filament 42 to be overloaded and therefore super-illuminated with an abnormally high intensity of light. This high intensity light, however, flashes only momentarily upon the fundus F as the plunger rod continues its rearward motion and the band 62 breaks the circuit between the contacts 65 and 84.

Immediately before the latter circuit is broken, however, the pin and slot connection |35, |34 between the end portion |36 or the plunger rod 51 and the bell crank lever |32 swings the latter around its pivot stud |31 and moves the prism cell |22 and prism |2| downward into the chain line position of Figure 1, removing the prism lili from the path of the rays leaving the photographic objective ||5. As the plunger rod 51 continues its rearward motion, the end of the portion |36 engages and swings the lower portion |69 of the shutter release lever |93, moving it out of engagement with the catch |59 on the shutter |49. Under the influence of the spring |00, the slit |53 of the shutter |49 moves rapidly past the film |54, exposing the lm and recording the image of the undus upon the film |54.

The film is then changed or transported to bring an unexposed portion into the focal plane of the magazine |55 in the manner customary in such magazines and forming no part of the present invention. The operator also resets the shutter by grasping the pin |59 (Figure 4) and sliding the shutter into the position shown in Figure 4 until the arm or catch |59 clicks past the upper end |62 of the shutter release lever |63, and is locked in position by the latter, ready for a new exposure to be made.

In order to definitely locate the portion of the fundus being photographed and to keep the eyeball motionless during the exposure, the patient is requested to fix his gaze on the illuminated spherical knob 53 upon one of the vertical rods 5I (Figure 2). If stereoscopic photographs are to be taken, the patient xes his gaze on one knob 53 for one exposure and upon the other knob for a subsequent exposure, the two exposures being then developed, printed, mounted and viewed in a stereoscope.

It will be understood that the prisms 93, |40 and I2| may be replaced by mirrors if it is so desired. It will also be obvious that the camera objective ||5 may be focussed by means other than the rack |09 and pinion |09, such as, for example, by a conventional spiral screw mount.

The modification shown in Figure 9 is intended to replace the xation rods 5| with their knobs 52. It consists of a sliding sleeve |95 mounted in a pair of aligned bores |96 in the opposite side walls of the casing halves I 3 and I4. The sleeve |95 terminates in flanges |91 and |98 and is of a greater length than the width of the casing I2, so that it may be slid from side to side.

The sleeve |95 is provided at its mid-portion with an elongated slot |99 leading to the longitudinal bore 200. Reciprocably mounted Avin the bore 200 is a rod having anged portions 202 and 203 at the opposite ends thereof. The rod 20| is longer than the sleeve |95 so as to be slidably axially thereof by an amount equal at least to the length of the slot |99. The rod 20| is provided with a transverse hole 204 in which is mounted the butt of a xation needle 205 which projects through the slot |99 with its pointed tip 206 substantially on the optical axis of the condensing lens system 81 and at the principal focus of the condensing lens 90.

The needle 205 thus is located substantially in the plane 9 9 in Figure 1. When the fixation device shown in Figure 9 is built into the instrument, the fixation knobs 53 and their rods 5| are omitted, along with the holes 52 through which they pass.

In the operation of the camera equipped with the modified fixation device of Figure 9, when the patient looks toward the aperture 24 in the nose plate 22, he sees an image of the needle 205, illuminated by the electric light bulb 40. Since the needle 295 is located at the prinicpal focus of the condensing lens system 81, rays emerging from the prism 93 are parallel and hence fail on the retina of an leye focussed for infinity. Thus, the patient fixes his gaze upon the image of the needle 205 rather than upon the fixation knobs 53 as in the principal form of the invention shown in Figure 1.

By sliding the sleeve |95 and rod 20| so as to move the needle 205 into the various positions indicated by the dotted line in Figure 9, as well as by the solid line position therein, the camera may be adjusted for photographing the fundus either of the right eye or the left eye, as well as for making stereoscopic views of the same eye.

What 1 claim is:

1. A fundus camera comprising a box-like casing having a forward portion projecting forwardly from the remainder of said casing, said forward portion having a nose member with a pair of adjacent openings, a photographic system in said casing having an objective lens spaced rearwardly of said nose member and al1gned with one of said openings, an illuminating system in said casing aligned with the other of said openings and including a projection lens, a camera positioning device for locating the camera at a predetermined position in iront of the eye being photographed, including a camera locating element interposed between said casing and a portion of the patients head containing the eye being photographed, an opaque lightmasking element between said openings positioned in the path of the rays from said illuminating system reflected from the cornea of the eye bemg photographed, an illuminated xation object in said casing arranged in the iocal plane of the projection lens of the illumination system for illumination thereby.

2. A undus camera comprising a box-like casing having a forward portion projecting forwardly from the rernalnder of said casing, said forward portion having a nose member with a pair of adjacent openings, a photographic system in said casing having an objective lens spaced rearwardly of said nose member and aligned with one of said openings, an illuminating system in said casing aligned with the other of said openings and including a projection lens, a camera positioning device for locating the camera at a predetermined position in front of the eye being photographed, including a camera locating element interposed between said casing Aand a portion of the patients head containing the eye being photographed, an opaque Alight-masking element between said openings positioned in the path of the rays from said illuminating system reflected from the cornea of the eye being photographed, an illuminated xation object in said casing arranged in the focal plane of the projection lens of the illumination system for illumination thereby, and a laterally shiftable support carrying said fixation element.

J OHN H, MCMILLIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Kuhl Dec. 31, 1929 15 Numbei` i2 Name Date Pfeiffer May 27, 1930 Clarke Sept, 30,- 1941 Nissel Apr. 14,1942 Wappler Apr. 21, 1942 Schwanzel Mau/19,1942 French 0011417, 1944 Cameron May 21 1946 Allen Nov. 18, 1947 Pearce Mayv 1.1, 1948 OTHER REFERENCES Journal of The Optical Society of America. March 1945, pages 187 to 189 inclusive. 

